In recent years, network connectable printers that can accept print jobs from a plurality of host computers linked in a LAN (Local Area Network) or other network have become prevalent, for example, in offices. In the case of adopting the foregoing network connectable printer, a host computer installs a printer driver for the control of the printing process at the printer (for example, as disclosed, in Patent Document 1: Japanese Laid-Open Patent Publication No. 2000-330742/2000 (Tokukai 2000-330742, published on Nov. 30, 2000)). The printer driver as installed serves as a program for controlling the printing on the host computer, and printing conditions in the printing process can be set by setting the printer driver.
The printer used in common among a plurality of host computers may be subjected to various restrictions on the print processing functions of the printer when carrying out a printing operation in consideration of users' preferences, efficiencies of a printing operation in the printer, etc.
For a printer in which a restriction on the printable number of pages in color print is set for each user, adopted, for example, is the structure wherein in an event that a set number of pages to color print is greater than the printable number of pages in the user's request for color print, the printing condition is changed automatically from color print to monochrome print, and a printing operation is executed in monochrome (for example, as disclosed, in Patent Document 2: Japanese Laid-Open Patent Publication No. 2002-103753/2002 (Tokukai 2002-103753, published on Apr. 9, 2002)). It may be also arranged such that in order to restrict the usable recording sheet, the use of the feed tray provided in the printer is restricted for each user. In such printer, upon making a request for a printing operation in which an unavailable feed tray is selected, the set condition for a feed tray is changed automatically to an available feed tray, and the printing operation is executed.
As another example, there is a printer wherein in the case where a request for both-sided printing operation is made by a user who has a permission for only under-printing, the set printing condition is changed automatically from the both-sided printing to the under-printing, thereby executing a under-printing operation.
As described, for a printer in which the print processing function is restricted for each user, in the case where a request for a printing operation is made with a print processing condition that is not permitted, printing conditions are changed automatically so that the printing operation is executed using a permitted print processing function.
However, as described in the foregoing printers, the printing conditions as requested by the user are changed automatically, and therefore, the printing operation may not be performed with the conditions desired by the user.
Specifically, for example, in the case where a request for color print is made with respect to a printer in which a color print is restricted, the condition is changed automatically from the color print to the monochrome print as described above. In this case, however, data for color print is still transmitted to the printer. Generally, the amount of data for color print is larger than the amount of data for monochrome printing, and therefore, it takes time to obtain a monochrome print. Besides, in the case where the printing conditions are changed automatically from the color printing to the monochrome printing, a file for monochrome printed sheets is prepared, and the printing conditions are set by the printer driver automatically, thereby presenting the problem that printed outputs as desired by the user may not be obtained.
Furthermore, in the case where the feed tray is changed automatically with the restriction on the print processing function, the feed tray as set automatically may not be the one the user desires. Similarly, for the printer in which a printing condition is charged automatically from the both-sided printing to the under-printing, and the printing operation in the under-printing is performed, the user may desire to change the print condition to multi-shot printing in which plural pages are printed on one under-sheet.
As described, according to the foregoing structure wherein the printing conditions are changed automatically, an unnecessary longer time is required for the printing operation, or the printing operation may not be performed with the printing condition as user desires.
Incidentally, the patent document 1 discloses the structure wherein the printer driver is installed automatically in the host computer; however, it fails to disclose the structure wherein a restriction on a print processing function is set for each host computer (user), or the structure wherein the print processing function is restricted on the printer driver.